Capacitor trimming system in a quartz-crystal oscillator
US4346537A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 1979 |
| Grant date | Aug 31, 1982 |
| Priority date | — |
| Expiry date | Nov 27, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49004
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A capacitor trimming system for a quartz-crystal oscillator in a watch and/or a clock for providing a punctual watch and/or a clock has been found. The system comprises an oscillation circuit including at least a quartz-crystal piece, a trimmer capacitor for adjusting the oscillating frequency of the quartz-crystal piece, a semiconductor electronic circuit for operating said quartz-crystal piece, and apparatus for adjusting automatically the trimmer capacitor so that the oscillating frequency becomes the same as the desired reference frequency. The trimmer capacitor comprises of at least a fixed outer trimming electrode, an inner common electrode fixed parallel to said trimming electrode and a dielectric body sandwiched between the two electrodes. The trimming electrode is disposed in the air for enabling the trimming of the area of the trimming electrode, and the trimming electrode has a coarse adjustment portion parallel and aligned with said common electrode and a fine adjustment portion attached to the same plane of that of the coarse adjustment portion but outside of the common electrode. The oscillation frequency of the quartz-crystal piece is automatically picked up and the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.